.\" Copyright (c) 2004 Gleb Smirnoff
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd May 14, 2019
.Dt NG_EIFACE 4
.Os
.Sh NAME
.Nm ng_eiface
.Nd "generic Ethernet interface netgraph node type"
.Sh SYNOPSIS
.In netgraph/ng_eiface.h
.Sh DESCRIPTION
The
.Vt eiface
netgraph node implements the generic Ethernet interface.
When an
.Vt eiface
node is created, a new interface appears which is accessible via
.Xr ifconfig 8 .
These interfaces are named
.Dq Li ngeth0 ,
.Dq Li ngeth1 ,
etc.
When a node is shut down, the corresponding interface is removed,
and the interface name becomes available for reuse by future
.Vt eiface
nodes.
New nodes always take the first unused interface.
.Sh HOOKS
An
.Vt eiface
node has a single hook named
.Va ether ,
which should be connected to the
Ethernet downstream, for example, to the
.Xr ng_vlan 4
node.
Packets transmitted via the interface flow out this hook.
Similarly, packets received on the hook go to the protocol stack as
packets received by any real Ethernet interface.
.Sh CONTROL MESSAGES
This node type supports the generic control messages, plus the following:
.Bl -tag -width foo
.It Dv NGM_EIFACE_SET Pq Ic set
Set link-level address of the interface.
Requires
.Vt "struct ether_addr"
as an argument.
This message also has an
.Tn ASCII
version, called
.Dq Li set ,
which requires as an argument an
.Tn ASCII
string consisting of 6 colon-separated hex digits.
.It Dv NGM_EIFACE_GET_IFNAME Pq Ic getifname
Return the name of the associated interface as a
.Dv NULL Ns -terminated
.Tn ASCII
string.
.It Dv NGM_EIFACE_GET_IFADDRS
Return the list of link-level addresses associated with the node.
.El
.Sh SHUTDOWN
This node shuts down upon receipt of a
.Dv NGM_SHUTDOWN
control message.
The associated interface is removed and its name becomes
available for reuse by future
.Vt eiface
nodes.
.Pp
Unlike most other node types, an
.Vt eiface
node does
.Em not
go away when all hooks have been disconnected; rather, an explicit
.Dv NGM_SHUTDOWN
control message is required.
.Sh SEE ALSO
.Xr netgraph 4 ,
.Xr ng_ether 4 ,
.Xr ng_iface 4 ,
.Xr ng_vlan 4 ,
.Xr ifconfig 8 ,
.Xr ngctl 8
.Sh HISTORY
The
.Vt eiface
node type was implemented in
.Fx 4.6 .
.Sh AUTHORS
.An -nosplit
The
.Vt eiface
node type was written by
.An Vitaly V Belekhov .
This manual page was written by
.An Gleb Smirnoff .
